Signaling system.



R. D. CONWAY.

SHSNALING SYSTEM- APPLICATION FILED JULY 9.1917.

Patented May 14, 1918.

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BOY D. CONWAY, OF CHAT-HAM, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC COM- PANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

SIGNALING SYSTEM.

Specification of Letters Iatent.

Patented ay 14, 1918.

Application filed m 9, 1917. Serial No. 179,416.

To all whom it may concern:

Be it known that 1, Her D. CONWAY, a citizen of the United States, residing at Chatham, in the county of Morris and State of New Jersey, have invented certain and useful Improvements in Signaling Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to signaling systems, and more specifically to signalin systems which are particularly applica le to signaling on composite telegraph and telephone circuits.

In certain telephone systems, particularly those in which both telegraph and telephone circuits are combined, it is desirable -to use, for signaling purposes, currents of different frequencies.

Especially in composite telegraph and telephone systems, it is desirable to use high frequency currents of approximately 133 cycles per second for the purpose of operating a signalin connection with the telephone service without interfering with the operation of the telegraph service. Since the standard type of signal used on telephone lines is arranged to respond only to a current of a much lower frequency, it is necessary to provide some means for translating the high frequency current into a current of such low frequency as will properly operate the telephone signal. The signaling current ordinarily used in connection with tele hone service has a low frequency, and, in 0rd eliminate the necessity of the operator using a special source of signaling current in connection with the composite lines only, it is desirable to provide means whereby the low frequency current is translated into a high frequency current suitable for transmission over such lines without interferingwith the telegraph service.

In signaling systems now in use in' connection with composited tele aph and telephone lines, considerable d' culty has been experienced due to the im roper operation of the apparatus caused y the signaling currents used for the telegraph service, or by the actuation of the switch hooks on the connected telephone lines. Due to these conditions as well as to the desirability of employing the same signaling equipment in connection with telephone lines of various lengths, it has been necessary in the past to provide a highly accurate adjustment of the er to actuating parts of the apparatus involved in one feature of this invention, a high impedance polarized relay with a vibratory armature is bridged across the conductors of a composited telephone line at a point intermediate the ends of the line. This relay is responsive to a signaling current of any frequency which may be applied at either end of the line and selectively controls local circuits containing tuned relays responsive to particular frequencies, for connecting to one end of the line a source of signaling current separate from that which is impressed on the other end of the line.

These and other features, not specifically mentioned above, will more clearly appear from the following specification and the annexed drawing in which the figure shows diagrammatically, suflicient of one end of a composited telephone lineto illustrate the invention.

In the. accompanying drawing the jack 1 and the drop 2 represent the terminus of a telephone lme which is composited. Although not shown on the drawing, since it is not essential to the proper understanding of the invention it is understood that the usual operators cord circuit equipped with the ordinary ringing device is available for connection with jack 1. The line conductors 15 and 16 may be assumed as connected with the line side of a regular composite circuit (not shown), which is associated with the telephone line under consideration and at the distant end of the telephone line (also not shown) there may be an arrangement similar to that shown in the drawing. It is thought that the invention may be more clearly understood from a description of the operation of the signaling system.

Assume that the operator at the station at signaling current of any frequency impressed on either end of said line, means responsive to a definite fre%uency of signaling current impressed on eit er end of the line selectively controlled by said first mentioned means, and means controlled by said last mentioned means for connectin a separate source of signaling current to t e other end of said line. i

2. In a si aling system, a line circuit, a polarized re ay connected to said line at an intermediate point and responsive to a penodically varying current at any frequency when impressed on either end of said line, means controlled by said polarized relay for producing in local circuits a current in syn chronism with that im ressed upon the line, and means included in said local circuits operable in response to a certain definite frequency for connecting a source of signaling current of a different frequency to the other end of the line.

3. In a signaling system, a line circuit, a polarized relay bridged across said line at an intermediate point thereof and responsive to currents of any frequency when impressed on either end of said line, a plurality of tuned relays selectively controlled by said polarized relay and each responsive to a particular frequency of current when current' of the corresponding frequency is impressed on said line, and means individual to and controlled by each of said tuned relays for connecting to one end of said line a signaling current having a frequency differing from that ofthe signaling current impressed on the other end of the said line.

4. In a signaling system, a line circuit, means connected to said line at an intermediate point thereof responsive to a signaling current of any frequency impremed on'either end of said line, means responsive to a definite frequency of signaling current impressed on either end of said line selectively controlled by said first mentioned means, and means controlled by said last mentioned means for interrupting the flow of said signaling current at said intermediate point of said line and for connecting a separate source of signaling current to the other end of said line. I I

5. In a signaling system, a line circuit, means connected to said line circuit at an intermediate point thereof responsive to signaling current of any frequency impressed on either end of said line, means responsive to a definite frequency of signaling current impressed on either end of said line selectively controlled by said first mentioned means, and means controlled by said last mentioned means for connecting a separate source of signaling current to the other end of the line and for preventing the transmission of the first mentioned 'gnaling current to the other end of said line.

6. In a signaling system, a line circuit, means connected to said line circuit atan intermediate point thereof responsive to a signaling current of any frequency impressed upon either end of said line, means responslve to a definite frequency of signaling current impressed on either end of said line selectively controlled by said first mentioned means, and means controlled by the last mentioned means for connecting the se arate source of signaling current to the other end of the line and for preventing the transmission of the signaling current past the first mentioned means. 4

7 In a signaling system, a line circuit, switching means responsive to a periodically varying current of any frequency impressed on either end of said line, two local circuits independent of said line circuit, means controlled by said switching means for producing a current in said local circuits in synchronism with the current impressed upon the line, and means controlled by current in said local circuits for impressing on the opposite end of said line signaling current having a different frequency.

8. In a signaling system, a line circuit, a polarized relay responsive to periodically varying currents of any frequency connected to the line circuit at an intermediate point thereof, means controlled by said polarized relay for producing in local circuits a current in synchro'nism with the current in the polarized relay, and means controlled by current in said local circuits for selecting and connecting to the line signaling current having a predetermined frequency difi'er'ing therefrom.

9. In a signaling system, a line circuit, two local circuits each arranged to connect one of two sources of periodically v arying currents of different frequencies to said line, switching means connected to said line at an intermediate point thereof responsive tora current of any frequency, and means con trolled by said switching means for selectively operating apparatus in one of said local circuits when a frequency correspond mg to that controlled by apparatus in the other of said local circuits is. lmpressed on either end of the line. i Y

10. In a signaling system, a line circuit, a polarized relay bridged across said line at an intermediate point thereof and having an armature adapted to vibrate in'synchronism with the frequency of any signaling current impressed on either end of said line, a tuned relay for each operative position of said armature responsive to one particular current frequency, local circuits arranged to be -closed by said polarized relay for operating each ofsaid tuned relays when a signaling current having its associated frequency is impressed on one end of said line, a plurality of sources of signaling current halving different frequencies corresponding to those on which the tunecl relays are responsive, and u plurality of eeleys controlled by each of said tuned relcys i501 connecting" to one end of said line one of sold sources of signaling current when it signaling current having e i i'eouency to which the tunecl we lay is responsive is impressed upon the other curl of said line,

11. in a signaling system, at line cii'cult, e polarised relcy bridged. across said line a t an intermediate point thereof ecleptecl to v1- bi'ute in synclironism with the signaling current of any frequency connected to eitlier end of said line and having on emetuie with two operative positions, two local Oilfcuits arranged to close when said etmeture is in either of its operative positions, at tunetl relay responsive to e particular frequency of 2c cui'i'ent only and e resistence connected. in

eecli oi? said locsl circuits, two sources of current haying tlifi ei'ent voltages arranged to be included in seifi. locel circuits upon the operation of seid armature to procluce in 25 both of seicl locel circuits e petioclicelly o rying current lliWllliP frequency in synchronism with the sigueling current opetet ing seicl nolerizeol relcy, two sources of pei'iodicelly VEIYllEf, signaling currents neving different frequencies, end e plurality of relays controlled by seen of said tuned relays for connecting to one encl oi seicl line one ct said sources of periodically verying cui'rent when e signaling; current bovine; e i esquency corresponding thet the other of said sources oi periodically verying current is impressed upon the other end of seicl line.

12. in a, signalling; system, a line circuit at polarized relay bridged ecrcss seiol line 6H- ouit et en intermediete point thereof and having an armature with two operative voositions end wronged. to -vibrate in synohionism with e signeling current oi eny litequency connected. to eithei euol oi said line, two local circuits" arranged to be closecl when eeiol emneture is in either oi its operetive positions, two sources oi? current hevine clin cient voltages arranged to includecl in said locsl circuits individually or in differential series relation upon the operation of said armature to produce in both of the said locel circuits e periodically varying current corresponding in frequency with the signaling current incni'esseel upon the line, e tunecl isle-y responsive to only one frequency oi current and e resistance included in each of seicl locel circuits, source oi periodicelly varying signeling current corresponding in i eequency with that to "which each oi seii tunetl i'eleys is responsive, encl e, plurality of relays GOl'liLZ'OllGCl loy each of seicl tuned to leye for connecting; to one end; of said line one of said sources of periodically varying current when the :celey responds to a cur rent OOITQSZ OOTMilHQ in {frequency with that of the othen seicl source of periodically vecurrent,

Witness 'Wlieteoi, ll hereunto subscribe my name this 3rd day of July, A, D, 191?,

D. QUNWAY. 

